Sited on a piece of land originally known as Ham Common, Richmond became an RAAF base in 1925. Its inaugural commander was Flight Lieutenant (later Squadron Leader) Frank Lukis, who also led the base's first flying unit, No. 3 Squadron. Many other squadrons were formed at Richmond in the ensuing years, as well as a separate Station Headquarters and No. 2 Aircraft Depot in 1936. The base expanded further during World War II, with more squadrons and other units being established there, including No. 1 (Fighter) Wing and No. 3 RAAF Hospital. It was not until after the war that it became the RAAF's transport hub, with the arrival of No. 86 Wing and its complement of C-47 Dakotas. The base began operating the Hercules in 1958, augmented in later years by the DHC-4 Caribou and Boeing 707.

Headquarters RAAF Base Richmond was formed in April 1952 to replace the former Station Headquarters, along with a subordinate unit, Base Squadron Richmond, for the day-to-day running of the establishment.[10] The base was evacuated in February 1956 due to the threat of rising floodwaters nearby, the only time in its history that flooding in the Hawkesbury region became serious enough to warrant such action.[10] In 1958–59, No. 36 Squadron began operating its first C-130 Hercules heavy transports,[12] which were augmented by No. 38 Squadron's DHC-4 Caribou tactical transports in 1964. No. 86 Wing was disbanded in August that year,[13][14] but reformed in February 1987, under the newly established Headquarters Air Lift Group that replaced the former Base Headquarters. At the same time, Base Squadron was reformed as Base Support Wing. No. 86 Wing took control of No. 33 Squadron, operating Boeing 707 jet tanker/transports, as well as Nos. 36 and 37 Squadrons, flying Hercules. No. 486 Maintenance Squadron and Air Movements Training and Development Unit (AMTDU) were also under its aegis at Richmond.[15] The Hercules, Caribous and 707s became synonymous with disaster relief and emergency transport in Australia and the region, as well as deploying on overseas peacekeeping missions. Richmond was the venue for many air shows including, in 1988, the largest staged in Australia to that date, celebrating the Australian Bicentenary.[5][16] The base also staged the RAAF's 70th Anniversary Air show in 1991, the same year that the Hercules achieved 500,000 accident-free hours of operation.[6]

By the early 2000s, No. 33 Squadron had been transferred to the recently re-established No. 84 Wing, and AMTDU to No. 85 Wing, while the Base Support Wing had been superseded by Combat Support Unit Richmond.[17] No. 36 Squadron, having transferred its C-130Hs to No. 37 Squadron and re-equipped with the C-17 Globemaster, relocated to RAAF Base Amberley, Queensland, in November 2006.[18] The RAAF's DHC-4 Caribous, which had been operated for some years by No. 38 Squadron out of RAAF Base Townsville, were retired at the end of 2009, to be replaced by Super King Airs built by Hawker Pacific.[19] No. 37 Squadron was transferred from No. 86 Wing to No. 84 Wing on 1 October 2010.[20] In January 2013, No. 35 Squadron was re-formed at Richmond, under the control of No. 84 Wing. Initially a cadre, the squadron will expand to approximately 250 personnel by 2015, when it will begin operating the RAAF's ten C-27J Spartan transport aircraft.[21][22]

In the 1980s, RAAF Base Richmond had been strongly considered as a second international airport for Sydney, but no decision was taken at the time.[16] By 2009, it was reported as being the New South Wales Government's preferred location for a secondary airport, but that any decision on a location would be the Federal Government's responsibility.[23] In July 2012, the Federal Government decided against Richmond as a second airport, but had commissioned a study into whether the base could be employed for "limited civil operations".[24]